Hydraulic press

ABSTRACT

A HYDRAULIC PRESS IS PROVIDED WITH A STATIONARY PRESS TABLE AND A MOVABLE FRAME STRUCTURE INCLUDING COLUMNS SLIDABLY MOVABLE IN THE TABLE AND CONNECTED ABOVE THE TABLE TO A CROSSHEAD AND BELOW THE TABLE TO A TRANSOM. ALL DRIVE AND POWER PISTON CYLINDER ARRANGEMENTS ARE SUPPORTED BY THE TABLE. THE PRESS IS ESPECIALLY SUITABLR FOR DENSIFYING POWDERIZED MATERIAL, FOR EXAMPLE, METAL POWER.

United States Patent [72] Inventor Rolfllermes Rheydt-Giesenkirchen, Germany 854,624

[2]] Appl. No. [22] Filed l Sept. 2', 1969 Patented June 28, 1971 [73] Assignee l/l9 65 Pqole et al.

Mannesmann-Meer Aktiengesellschaft, Primary ExaminerH. A. Kilby, Jr. Monchengladbach. Germany Attorney-Nolte and Nolte Sept. 5, 1968 Germany P 17 77 094.4

ABSTRACT: A hydraulic press is provided with a stationary ress table and a movable frame structure including columns 11 Clams 3 Drawing Flgs' slidably movable in the table and connected above the table to [52] US. Iii/16.5 a crosshead and below the table to a transom. All drive and [51] B29c 3/00 l8/l6(R), 16 (P), 16.5, 30 (LV) [32] Priority [54] HYDRAULIC PRESS power piston cylinder arrangements are supported by the tamm mm "S I a d Ld mm m U ble. The press is especially suitable for densifying powderized (Dig.) 35 a material, for example, metal powder.

PATENIED JUN28 IBTI SHEET 1 BF 3 Inventor.-

ROLF HERMES BY MWMQ' ATTORNEYS PATENTEU JUN28 I971 SHEET 2 BF 3 Inventor- ROLF HERMES 7Ma 42M; ATTORNEYS PATENTEU JUH28 |97| SHEET 3 UP 3 Fig.3

Inventor:

ROLF HERMES BY ma 4% ATTOR EYS HYDRAULIC PRESS The present invention relates to a hydraulic press having a press frame, including an upper crosshead and a lower transom connected to each other by column means, especially for densifying pulverized materials such as metal powders.

It is known that presses of this type require a heavy frame adapted to receive and support two cylinders. Such frame must be variable in its dimensions in order to adapt it to different available installation heights whereby, due to the upper cylinder, the entire height of the press above the floor may become substantial.

In such presses the container for the hydraulic fluid is commonly arranged on top of the press; this has its advantage with regard to placing the hydraulic conduits, however, it causes a still further increase of the total height of the press.

On the other hand, if the container for the. hydraulic fluid is placed on the floor the supply of the hydraulic fluid to the cylinder becomes difficult due to the high location of the cylinder relative to the position of the hydraulic fluid container. In such a structure the filling valves for the hydraulic fluid conduits are arranged on top of the press and, therefore, it is difficult to gain access to these valves whereby it cannot be avoided that leaking hydraulic fluid, such as oil from the upper cylinder, comes into contact with the material to be pressed.

In order to avoid these difficulties a press combination has been proposed in which only the lower die stamp is actuated by hydraulic means and the motion of the lower die stamp causes the simultaneous release of the movement of the upper die in the direction opposite to the movement of the lower die stamp, such release being accomplished through linkage and lever arrangements. However, such linkage and lever arrangements assume uneconomical shapes where large pressing powers are to be transmitted. Therefore, this type of structure is limited in its pressing power.

In view of the above it is an object of the invention to avoid the outlined drawbacks.

A more specific object of the invention is to reduce the structural height and weight of a press without reducing the pressing power.

Yet another object of the invention is to provide good accessibility to the vital members of the press for easy repair and maintenance.

A still further object of the invention is to provide easy accessibility and visibility of the die means of the press.

Yet another object of the invention is to avoid hydraulic liquid leakage, especially of any upper die means.

It is also an object of the invention to place the center of gravity of the entire structure as low as possible.

Briefly, according to the invention, the above objects have been achieved by a press structure in which a press table is held in a stationary and fixed position, by means of two claws or strips anchored in the foundation of the press. The table comprises two upwardly extending sidewalls which provide therebetween sufficient space for locating or clamping the tool means on the press table. Two single-acting power cylinders are supported opposite each other in the press table and the corresponding power pistons are connected to a, preferably ring-shaped, transom located beneath the table. The transom surrounds a lower cylinder centrally attached to the press table. The transom is connected to an upper crosshead by four columns, said upper crosshead supporting an upper die stamp. The guiding supports or bearings for said columns are located in the lower portion of said press table and in the upper portion of said upright sidewalls. The support of the columns over a substantial length in said table and upright walls and the connection of the column ends above the table to the crosshead and below the table to the transom results in a structure which is rigid with regard to torsional forces and which transmits through laterally positioned hydraulic cylinders the press motion of the upper die stamp while the piston of the lower cylinder releases the movements of a matrix relative to a stationary lower die stamp. Further, two additional pistons attached to the upper crosshead and cooperating with two cylinders attached to the table in diametrically opposite positions, provide the idle return stroke of the upper die stamp in a rapid traverse movement.

The construction, according to the invention, has the advantages that the entire height of the press has been reduced, that the leakage of the upper die stamp means has been eliminated and that a rather simple overall structure has been achieved by means of a crosshead, a transom and four columns which simultaneously reduce the weight substantially. Arranging the hydraulic cylinders in the stationary press table not only provides good visibility, but it also facilitates the maintenance of the hydraulic system since all elements to be serviced are in easily accessible positions. Besides, the center of gravity has been placed close to the anchoring members in the foundation.

In order that the invention may be clearly understood, it will now be described, by way of example, with reference to the accompanying drawings, wherein:

FIG. I is a front view, partially in section, of a press according to the invention;

FIG. 2 is a side view of the press, according to FIG. 1 and partially in section; and

FIG. 3 is a top view ofthe press shown in FIGS. 1 and 2.

Referring to FIGS. 1 and 2, the press table 1 is supported in a fixed position by anchoring members 2 attached to foundation members 25, 26. The table 1 comprises two upright walls 3 located opposite each other and along two sides of the table 1. The walls 3 provide sufficient space therebetween for locating or clamping tool means 4 on the table 1.

Two hydraulic cylinders 5 are supported in the table opposite each other. Pistons 6 are slidably guided in the cylinders 5 and are connected to a transom 7 located underneath the table 1. The transom 7 may preferably be a frame or ring structure. In the center of the table and therebelow there is arranged a lower cylinder 8, the lower end of which is surrounded by the ring-shaped transom 7. The cylinder 8 has a piston 9 slidable therein which extends through the table 1 and which moves a matrix 10 up and down while a lower die stamp 21 of the tool 4 remains stationary.

The upright walls 3 of the press table I support two cylinders 11 which are arranged diametrically opposite each other as best seen in the top view of FIG. 3. Pistons 12 which slidejn said cylinders 11 are connected to a crosshead 13 supported by columns 15 above the table 1 and movable relative to the table by said cylinder piston means 11 and 12 as best seen in FIG. 2.

An upper member of the die, such as an upper stamp 14, is attached to the crosshead 13.

Furthermore, the crosshead 13 is connected to said transom 7 in a rigid manner by said columns 15. Preferably, there are four such columns. The connection between the column ends and the transom and the crosshead may, for example, be accomplished by threaded members 27. This structure of the press assures, in combination with the substantial length between adjacent column guide bearings 16, 17, 18 and 19, that the frame is rigid against torsional forces.

The motion of the frame structure may be limited by stop members 20 attached opposite each other to the crosshead and to the top of the upright walls 3. The stop members 20 may be adjustable in height by threaded means 28. Preferably these stop members 20 are also arranged diagonally opposite each other to complement the cylinder piston means 1! and 12 to achieve a symmetric structure as best seen in FIGS. 2 and 3.

The operation of the press, according to the invention, is as follows:

FIGS. 1 and 2 illustrate the operational members of the press ready to be triggered. The pressure conduits, as well as the hydraulic fluid containers and filling funnels, since they are known per se, have been omitted for the sake of clarity. The matrix I0 is shown in FIG. I, in addition to the full line position, in a dash-dotted position in which the matrix is ready to he filled with a powderized material.

The control of the hydraulic cylinders 5, 11 is arranged in such a manner that the necessary movements and the application of force coact with each other in synchronism and in dependency on each other so that any dead time is substantially eliminated. To this end the piston 9 moves the matrix 10 into its filling position where it is filled while simultaneously the upper die stamp 14 starts, driven by the piston 12 in a rapid traverse motion, toward its power stroke whereby the lateral pistons 6 are taken along without power transmittal by means of the crosshead 13, columns and transom 7.

When the upper die stamp 14 hits the column of powder material in the matrix 10 the power of the lateral piston 6 becomes effective and the actual press or power stroke is carried out whereby the matrix 10 is taken along in a manner known per se due to the friction between its inner wall and the downwardly moving die stamp 14. During this downward stroke of the upper die stamp 14 the lower die stamp 21 remains stationary.

When the downward power stroke is completed the upper die stamp 14 is lifted in a rapid traverse motion by the pistons 12 which move the crosshead 14 back into its starting position. Simultaneously, the matrix is pulled off the upper die stamp 14 by the piston 9 which returns the matrix 10 to its starting position. By returning the matrix 10 to its starting position, as shown in full lines in HO. 1, the blank is stripped from the matrix and can thus be removed from the press whereupon the just described steps may be repeated continuously.

lclaim:

1. In a hydraulic press having a press frame including an upper crosshead and a lower transom as well as column means having lower and upper ends for connecting said crosshead and said transom with each other the improvement, comprising: a stationary press table, upright wall means supported on said press table and arranged opposite each other, said column means extending through the table and walls and being supported for axial movement, said lower transom being located underneath the table and rigidly connected to said lower ends of said column'means, said crosshead being located above the table and rigidly connected to said upper column ends, cooperating tool means attached to the crosshead and supported by said press table, and hydraulic piston cylinder means operatively connected between said table and said transom as well as said crosshead for actuating the same.

2. The hydraulic press according to claim 1, wherein said cylinder means are supported by said stationary press table.

3. The hydraulic press according to claim 1, wherein said hydraulic piston cylinder means comprise two drive cylinders arranged diametrically opposite each other in said upright wall means, and two drive piston means each slidable in its respective drive cylinder and connected to said crosshead.

4. The hydraulic press according to claim 1, wherein said hydraulic piston cylinder means further comprise two power cylinders supported in said press table and two power pistons each slidable in its respective power cylinder and connected to said transom.

5. The hydraulic press according to claim 4, wherein said power piston cylinder means are of the single-acting type.

6. The hydraulic press according to claim 4, wherein said power cylinders are arranged opposite each other in said stationary press table.

7. The hydraulic press according to claim 1, wherein said transom is a frame structure.

8. The hydraulic press according to claim 1, wherein said transom has a ring shape.

9. The hydraulic press according to claim 1, wherein said cooperating tool means comprise a die stamp attached to said crosshead and a lower die stamp as well as a matrix supported centrally of said table.

10. The hydraulic press according to claim 9, further comprising a piston cylinder arrangement located centrally of said table, said matrix being supported by the piston of said piston cylinder arran ement.

11. The hy rauhc press according to cla|rn 3, further comprising stop means arranged diametrically opposite each other on said upright walls and said crosshead in positions complementary to said drive cylinder piston means. 

